U.S. patent application number 16/471108 was filed with the patent office on 2019-10-31 for controller for a motor vehicle, motor vehicle, and method for controlling a motor vehicle.
This patent application is currently assigned to VOLKSWAGEN AKTIENGESELLSCHAFT. The applicant listed for this patent is VOLKSWAGEN AKTIENGESELLSCHAFT. Invention is credited to Christian JUNGNICKEL, Jens WODAUSCH.
Application Number | 20190329775 16/471108 |
Document ID | / |
Family ID | 60654974 |
Filed Date | 2019-10-31 |
United States Patent
Application |
20190329775 |
Kind Code |
A1 |
JUNGNICKEL; Christian ; et
al. |
October 31, 2019 |
CONTROLLER FOR A MOTOR VEHICLE, MOTOR VEHICLE, AND METHOD FOR
CONTROLLING A MOTOR VEHICLE
Abstract
A controller for a motor vehicle (1) has an internal combustion
engine (3), a transmission (4), and a cooling device (5) with a
coolant (5b) for cooling the internal combustion engine (3),
wherein the controller (2) is configured to determine a target
minimum rotational speed for the internal combustion engine (3) on
the basis of the temperature of the internal combustion engine (3)
and/or the temperature of the coolant (5b) and to determine a
target gear setting on the basis of the target minimum rotational
speed.
Inventors: |
JUNGNICKEL; Christian;
(Ribbesbuttel, DE) ; WODAUSCH; Jens;
(Braunschweig, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VOLKSWAGEN AKTIENGESELLSCHAFT |
Wolfsburg |
|
DE |
|
|
Assignee: |
VOLKSWAGEN
AKTIENGESELLSCHAFT
Wolfsburg
DE
|
Family ID: |
60654974 |
Appl. No.: |
16/471108 |
Filed: |
December 11, 2017 |
PCT Filed: |
December 11, 2017 |
PCT NO: |
PCT/EP2017/082115 |
371 Date: |
June 19, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60W 50/14 20130101;
F01P 2031/20 20130101; B60W 2050/146 20130101; F01P 11/16 20130101;
B60W 10/11 20130101; B60R 16/0231 20130101; F01P 2025/66 20130101;
B60W 2710/0688 20130101; B60W 30/1843 20130101; B60W 2510/0638
20130101; B60W 2710/0644 20130101; B60W 10/06 20130101; B60W
2510/1005 20130101; B60W 2552/15 20200201; F01P 2050/22 20130101;
B60W 2510/0676 20130101; B60W 2710/1005 20130101 |
International
Class: |
B60W 30/184 20060101
B60W030/184; B60W 10/06 20060101 B60W010/06; B60W 10/11 20060101
B60W010/11; F01P 11/16 20060101 F01P011/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2016 |
DE |
10 2016 225 421.9 |
Claims
1. A controller for a motor vehicle that has an internal combustion
engine, a transmission and a cooling device with a coolant in order
to cool the internal combustion engine, whereby the controller is
configured to: determine a target minimum rotational speed for the
internal combustion engine on the basis of the temperature of the
internal combustion engine and/or on the basis of the temperature
of the coolant; and determine a target gear setting on the basis of
the target minimum rotational speed.
2. The controller according to claim 1, whereby the transmission is
configured as an automatic transmission and the controller is
configured to control the transmission on the basis of the
determined target gear setting.
3. The controller according to claim 1, whereby the transmission is
configured as a manual transmission and the controller is
configured to issue a gear recommendation on the basis of the
determined target gear setting.
4. The controller according to claim 1, whereby the target minimum
rotational speed is determined in order to minimize the thermal
loading of the internal combustion engine.
5. The controller according to claim 1, whereby the target minimum
rotational speed is determined if the temperature of the internal
combustion engine exceeds a temperature threshold value and/or if
the temperature of the coolant exceeds a temperature threshold
value.
6. The controller according to claim 1, whereby the controller has
an engine control section and a transmission control section,
whereby the engine control section determines the target minimum
rotational speed and the transmission control section determines
the target gear setting.
7. The controller according to claim 6, whereby the motor vehicle
has a data bus, and whereby the engine control section transmits
the target minimum rotational speed to the transmission control
section via the data bus.
8. The controller according to claim 1, whereby the determination
of the target minimum rotational speed is carried out
incrementally.
9. A motor vehicle that has an internal combustion engine, a
transmission and a cooling device with a coolant in order to cool
the internal combustion engine, as well as a controller according
to claim 1.
10. A method for controlling a motor vehicle that has an internal
combustion engine, a transmission and a cooling device with a
coolant in order to cool the internal combustion engine, whereby
the method comprises: determining a target minimum rotational speed
for the internal combustion engine on the basis of the temperature
of the internal combustion engine and/or on the basis of the
temperature of the coolant; and determining a target gear setting
on the basis of the target minimum rotational speed.
11. The method according to claim 10, whereby the transmission is
configured as an automatic transmission and the method further
comprises controlling the transmission on the basis of the
determined target gear setting.
12. The method according to claim 10, whereby the transmission is
configured as a manual transmission and the method further
comprises issuing a gear recommendation on the basis of the
determined target gear setting.
13. The method according to claim 10, whereby the target minimum
rotational speed is determined in order to minimize the thermal
loading of the internal combustion engine.
14. The method according to claim 10, whereby the target minimum
rotational speed is determined if the temperature of the internal
combustion engine exceeds a temperature threshold value and/or if
the temperature of the coolant exceeds a temperature threshold
value.
15. The method according to claim 10, whereby the determination of
the target minimum rotational speed is carried out incrementally.
Description
[0001] The invention relates to a controller for a motor vehicle,
to a motor vehicle having such a controller, and to a method for
controlling a motor vehicle, especially in the realm of motor and
transmission control.
[0002] In general, it is a known procedure to control the drive
train of a motor vehicle, whereby the drive train can have, among
other things, an internal combustion engine and a transmission.
[0003] German Preliminary Published Application DE 10 2004 002 761
A1 discloses a method for operating a drive train of a motor
vehicle, whereby the drive train has a drive machine, a
transmission and a control device. The control device limits the
torque of the drive machine in order to protect the transmission.
For this purpose, the control device evaluates information about
the temperature of the transmission and limits the torque as a
function of the temperature information.
[0004] A method for reducing the thermal loading of an automatic
transmission for a motor vehicle in case of emergency is known from
German Preliminary Published Application DE 198 44 618 A1. The
thermal loading of the automatic transmission is reduced in that a
permissible maximum engine torque is prescribed for emergency
driving operation.
[0005] The cited documents from the state of the art have the
drawback that they only take into account the state of the
automatic transmission.
[0006] In a motor vehicle that has an internal combustion engine
and an automatic transmission, however, it is also known that, for
example, during mountainous driving, the transmission control unit
prescribes the highest gear, which can mean that the internal
combustion engine has to deliver its maximum torque. This can cause
a high thermal loading of the cooling system of the internal
combustion engine. In an extreme case, the temperature of the
coolant of the cooling system can rise to such an extent that
emergency measures are taken such as, for example, shutting down
the air-conditioning, reducing the torque delivered by the internal
combustion engine, actuating a warning light indicating that the
temperature of the internal combustion engine is too high, or the
like.
[0007] The objective of the present invention is to put forward a
controller for a motor vehicle that has an internal combustion
engine, a transmission and a cooling device, to put forward a motor
vehicle having such a controller, and to put forward a method for
controlling a motor vehicle that has an internal combustion engine,
a transmission and a cooling device, said controller at least
partially overcoming the above-mentioned drawbacks.
[0008] This objective is achieved by the controller of the
invention according to claim 1, by the motor vehicle according to
claim 9 and by the method according to claim 10.
[0009] According to a first aspect, the present invention puts
forward a controller for a motor vehicle, whereby the motor vehicle
has an internal combustion engine, a transmission and a cooling
device with a coolant in order to cool the internal combustion
engine, and whereby the controller is configured to:
[0010] determine a target minimum rotational speed for the internal
combustion engine on the basis of the temperature of the internal
combustion engine and/or on the basis of the temperature of the
coolant; and
[0011] determine a target gear setting on the basis of the target
minimum rotational speed.
[0012] According to a second aspect, the present invention puts
forward a motor vehicle that has an internal combustion engine, a
transmission, a cooling device with a coolant in order to cool the
internal combustion engine, and a controller according to the first
aspect.
[0013] According to a third aspect, the present invention puts
forward a method for controlling a motor vehicle that has an
internal combustion engine, a transmission and a cooling device
with a coolant in order to cool the internal combustion engine,
whereby the method comprises:
[0014] determining a target minimum rotational speed for the
internal combustion engine on the basis of the temperature of the
internal combustion engine and/or on the basis of the temperature
of the coolant; and
[0015] determining a target gear setting on the basis of the target
minimum rotational speed.
[0016] Additional advantageous aspects of the invention ensue from
the subordinate claims and from the description below of preferred
embodiments of the present invention.
[0017] As mentioned above, for example, in a motor vehicle that has
an internal combustion engine and an automatic transmission, it is
known that, during mountainous driving, the transmission control
unit prescribes the highest gear, which can mean that the internal
combustion engine has to deliver its maximum torque, which entails
all of the other above-mentioned consequences.
[0018] In order to solve this problem, one could visualize
adjusting the shifting characteristic map in the transmission
control unit. However, this could cause the internal combustion
engine to be operated at a higher rotational speed. Selecting a
lower gear typically causes an increase in the volumetric flow in
the internal combustion engine. Due to the mechanically coupled
cooling water pump, the water volumetric flow in the cooling system
is directly proportional to the rotational speed of the engine. At
the same time, the reduced load demand at the same output can lead
to a lower energy input into the cooling system.
[0019] Consequently, with this visualized solution, however, no
dynamic intervention would be possible in case of an elevated
temperature, since the downshifting points in the transmission are
typically specified during the development phase. If the motor
vehicle or the internal combustion engine is overloaded by a user,
the prescribed temperature limits might be exceeded. Another
increase in the rotational speed or a downshifting would no longer
occur since the downshifting points were specified during the
development phase.
[0020] The emergency cascade specified in such a visualized
solution, which, as mentioned above, can comprise, for example,
shutting down the air-conditioning, a heat warning light and torque
reduction, involves defined steps that are checked in the motor
vehicle in conjunction with the permissible total weight and
permissible towing capacity. However, such an emergency cascade has
perceptible drawbacks such as the lack of air-conditioning and
diminished driving performance.
[0021] Consequently, as also mentioned above, some embodiments
relate to a controller for a motor vehicle that has an internal
combustion engine, a transmission and a cooling device with a
coolant in order to cool the internal combustion engine. The
controller is configured to determine a target minimum rotational
speed for the internal combustion engine on the basis of the
temperature of the internal combustion engine and/or on the basis
of the temperature of the coolant, and to determine a target gear
setting on the basis of the target minimum rotational speed.
[0022] The controller can have typical elements of a motor vehicle
controller such as one or more processors, a memory, logic circuit
elements, etc.
[0023] The internal combustion engine can be a gasoline engine, a
diesel engine or the like, and the present invention is not
restricted to a specific type of internal combustion engine.
[0024] The transmission can be a manual, a semi-automatic or a
fully automatic transmission of the types fundamentally known to
the person skilled in the art.
[0025] The cooling device can have an (air) cooler in which the
coolant is cooled. The coolant can be water-based as is generally
the case.
[0026] The target minimum rotational speed can fundamentally be
selected as a function of the specifications of a concrete internal
combustion engine and of a concrete cooling device. Here, the
dependence of the target minimum rotational speed on the
temperature of the internal combustion engine or on the temperature
of the coolant can have been specified in advance. This dependence
can be configured as a threshold value so that, for example, if a
threshold value for the temperature of the internal combustion
engine or for the temperature of the coolant is exceeded, then a
prescribed target minimum rotational speed is determined. However,
the dependence can also relate to a prescribed function and can be,
for instance, linear, exponential or the like, so that, for
example, when the temperature rises, the target minimum rotational
speed also rises. In this context, the dependence can be stored in
the form of a table in the controller, for example, in the memory,
or as a formula, so that the target minimum rotational speed is
determined as needed on the basis of the formula, that is to say,
it is calculated in this case.
[0027] A target gear setting is determined on the basis of the
target minimum rotational speed. The target gear setting is not the
same as the one that leads to the target minimum rotational speed
in every embodiment, but rather the target gear setting can be
selected in such a way that the momentary rotational speed of the
internal combustion engine changes in the direction of the target
minimum rotational speed.
[0028] The invention entails the advantage that the driving comfort
and the availability of the interior air-conditioning can be
improved, especially as compared to the above-mentioned visualized
solution, since, for example, the cited emergency cascade is not
used, and consequently the air-conditioning system does not have to
be shut down. Moreover, the thermal loading of the internal
combustion engine and for auxiliary components can be reduced.
Furthermore, the application resources in the transmission or in
the controller (gear controller) can be reduced. Some embodiments
allow an as-needed rotational speed specification for the engine in
order to minimize the thermal load and to maximize the customer
comfort.
[0029] As already mentioned, the transmission can be configured as
an automatic transmission and the controller can also be configured
to control the transmission on the basis of the determined target
gear setting. As a result, the gear setting can be automatically
changed in accordance with the target gear setting.
[0030] The transmission can also be configured as a manual
transmission and the controller can also be configured to issue a
gear recommendation on the basis of the determined target gear
setting. In this manner, a user can be told to select another gear
that brings about a change from the momentary rotational speed of
the internal combustion engine to the target minimum rotational
speed.
[0031] The target minimum rotational speed can be determined in
order to minimize the thermal loading of the internal combustion
engine. Here, for example, the thermal load can be determined in
advance as a function of the internal combustion engine. This means
that the relationship between the rotational speed and the thermal
loading of the internal combustion engine can be known in the case
of some embodiments. Accordingly, the target minimum rotational
speed can be determined in such a way that the thermal load is
minimized to a prescribed or predetermined extent. Consequently,
the thermal load can be systematically controlled and
influenced.
[0032] The target minimum rotational speed can be determined if the
temperature of the internal combustion engine exceeds a temperature
threshold value and/or if the temperature of the coolant exceeds a
temperature threshold value. As a result, the target minimum
rotational speed can be determined as a function of the temperature
threshold so that the controller only intervenes in this case.
[0033] The controller can have an engine control section and a
transmission control section, whereby the engine control section
determines the target minimum rotational speed and the transmission
control section determines the target gear setting. This makes it
possible to arrange the engine control section and the transmission
control section at a distance from each other or else to provide
the appertaining function in control units that are already present
such as, for example, the engine control unit and the transmission
control unit.
[0034] The motor vehicle can also have a data bus such as a CAN
bus, Flex bus or the like, and the engine control section can
transmit the target minimum rotational speed to the transmission
control section via the data bus. In this manner, the determined
target minimum rotational speed information can be transmitted to
the transmission control section that then determines the target
gear setting on this basis.
[0035] The determination of the target minimum rotational speed can
be carried out incrementally. This makes it possible to lower the
temperature of the internal combustion engine or of the coolant in
stages. For example, first of all, the next-lower gear with the
associated target minimum rotational speed can be selected. If it
turns out, for instance, that the temperature of the internal
combustion engine or of the coolant is still above a temperature
threshold value, then the next-lower gear with the associated
target minimum rotational speed can be determined, etc. As a
result, an incremental control of the temperature of the internal
combustion engine or of the coolant is possible and larger shifting
increments in the transmission can be avoided.
[0036] Some embodiments relate to a motor vehicle as described
above that has an internal combustion engine, a transmission, a
cooling device with a coolant in order to cool the internal
combustion engine, and a controller as described herein.
[0037] Some embodiments relate to a method for controlling a motor
vehicle, as described herein, that has a transmission, an internal
combustion engine, and a cooling device with a coolant in order to
cool the internal combustion engine. The method comprises the steps
that were also already described above in conjunction with the
controller, namely, determining a target minimum rotational speed
for the internal combustion engine on the basis of the temperature
of the internal combustion engine and/or on the basis of the
temperature of the coolant, and determining a target gear setting
on the basis of the target minimum rotational speed.
[0038] The method can be carried out, for example, by the
controller described herein.
[0039] As explained, the transmission can be configured as an
automatic transmission and the method can also comprise controlling
the transmission on the basis of the determined target gear
setting. The transmission can be configured as a manual
transmission and the method can also comprise issuing a gear
recommendation on the basis of the determined target gear setting.
The target minimum rotational speed can be determined in order to
minimize the thermal loading of the internal combustion engine. As
mentioned, the target minimum rotational speed can be determined if
the temperature of the internal combustion engine exceeds a
temperature threshold value and/or if the temperature of the
coolant exceeds a temperature threshold value.
[0040] Embodiments of the invention will now be described by way of
example and making reference to the accompanying drawing, in
which:
[0041] FIG. 1 schematically shows an embodiment of a motor vehicle
with a controller,
[0042] FIG. 2 schematically shows the controller for the motor
vehicle with the actuated components, and
[0043] FIG. 3 shows a flow chart of a method for controlling the
motor vehicle depicted in FIG. 1.
[0044] An embodiment of a motor vehicle 1 with a controller 2 is
schematically shown in FIG. 1.
[0045] The motor vehicle 2 has an internal combustion engine 3. The
internal combustion engine 3 is configured as a 4-cylinder gasoline
engine, but without the invention being restricted in this
respect.
[0046] The internal combustion engine 3 is coupled via a drive
shaft to a transmission 4, whereby the transmission 4 is configured
as an automatic transmission, for example, as a conventional
dual-clutch transmission.
[0047] Moreover, a cooling device 5 is provided that cools the
internal combustion engine 3 by means of a cooler 5a that is filled
with a coolant 5b in a generally known manner.
[0048] In order to determine the temperature of the internal
combustion engine 3, there is a temperature sensor that measures
the oil temperature and thus the temperature of the internal
combustion engine 3.
[0049] In order to determine the temperature of the coolant 5b,
there is another temperature sensor 7 in the coolant circuit of the
cooling device 5.
[0050] In the embodiment shown in FIG. 1, the controller 2 is
coupled to the internal combustion engine 3, to the transmission 4,
to the temperature sensor 6 and to the temperature sensor 7.
[0051] FIG. 2 shows another embodiment in which the controller 2 is
made up of an engine control section 2a (e.g. engine control unit)
and a transmission control section 2b (e.g. transmission control
unit) that can communicate with each other via a CAN bus 9.
[0052] In the embodiment shown in FIG. 2, the temperature sensor 7
is coupled to the CAN bus 9 and it transmits temperature values to
the engine control section 2a via said CAN bus 9.
[0053] The engine control section 2a is coupled directly to the
internal combustion engine 3 and to the associated temperature
sensor 6.
[0054] The transmission control section 2b is coupled directly to
the transmission 4.
[0055] Moreover, a shifting recommendation display 8 can optionally
be issued, as will also be explained below.
[0056] Below, the mode of operation of the controller 2 and of the
control sections 2a and 2b will be explained with reference to the
flow chart shown in FIG. 3, which depicts the sequence of a method
10 for controlling the motor vehicle 1 of FIG. 1.
[0057] In step 11, the method 10 first determines the target
minimum rotational speed for the internal combustion engine 3 on
the basis of the temperature of the internal combustion engine 3
and/or on the basis of the temperature of the coolant 5b. For this
purpose, the engine control section 2a receives the appertaining
temperature values from the temperature sensor 6, which determines
the temperature of the internal combustion engine 3, and/or the
engine control section 2a receives the appertaining temperature
values from the temperature sensor 7, which determines the
temperature of the coolant 5b.
[0058] As already indicated above and explained in greater detail
below, there are embodiments in which the target minimum rotational
speed is determined only on the basis of the temperature of the
coolant 5b or on the basis of the temperature of the internal
combustion engine 3. In such embodiments, the superfluous
temperature sensor can be dispensed with. For instance, in
embodiments that make use of the temperature of the coolant 5b, the
temperature sensor 6 can be left out, and in embodiments that make
use of the temperature of the internal combustion engine 3, the
temperature sensor 7 can be left out.
[0059] The engine control section 2a determines, as already
mentioned, an appertaining target minimum rotational speed on the
basis of the temperature. This target minimum rotational speed is
about 4000 rpm, for example, above a coolant temperature of
115.degree. C., whereby the temperature of 115.degree. C. is set as
the temperature threshold value, without the invention being
restricted to this concrete example.
[0060] In embodiments in which the target minimum rotational speed
is determined on the basis of the temperature of the internal
combustion engine 3, the temperature threshold value can be set,
for example, at 110.degree. C. and, on this basis, a target minimum
rotational speed of about 4000 rpm can be determined, without the
invention being restricted to this concrete example.
[0061] In step 12, the controller 2 determines a target gear
setting. This can be done in that the engine control section 2a
provides the minimum rotational speed and/or issues a shifting
recommendation that, for example, actively prevents the
transmission 4 from up-shifting, so that an operating point at a
high rotational speed and at a low load is established.
Consequently, the cooling system, as explained above, is thermally
relieved and the emergency cascade does not have to be activated,
so that there are no adverse effects for the customer in terms of
the interior air-conditioning or the drivability.
[0062] However, the engine control section 2a can also transmit the
target minimum rotational speed, for example, in that it activates
an already present message on the drive-CAN 9, for instance,
ENGINE_Prio_MIN_target_rotational_speed, in order to indicate to
the transmission 4 or to the transmission control section 2b that a
target minimum rotational speed has to be set.
[0063] In response to the CAN message
ENGINE_MIN_target_rotational_speed that is already present, the
target minimum rotational speed determined or needed by the engine
control section 2a is sent, and then received by the transmission
control section 2b and processed.
[0064] Therefore, if the momentary rotational speed of the internal
combustion engine 3 is below the target minimum rotational speed
that the engine control section 2a has determined, then, in step
13, the transmission 4 downshifts by appropriately controlling the
transmission control section 2b to such an extent that the target
minimum rotational speed is maintained.
[0065] As an alternative, in some embodiments, the rotational speed
specification can be cascaded as a function of the temperature of
the internal combustion engine 3 so that the engine control section
2a raises the target minimum rotational speed incrementally. If,
for example, the downshifting by one gear is not sufficient to
increase the cooling output, then another speed increase of the
target minimum rotational speed can be effectuated, as a result of
which steps 11 and 12 are repeated, for instance, in a loop.
Assuming a constant output, which is necessary, the cooling mass
flow rises and the required torque drops once again.
[0066] In some embodiments, the transmission 4 is configured as a
manual transmission.
[0067] In such embodiments, for instance, the controller 2 can
determine the target minimum rotational speed in step 11 and the
target gear setting in step 12, as was explained above. Then in
step 14, as an alternative to step 13, the controller 2 can issue a
shifting recommendation and can control the shifting recommendation
display 8 accordingly, so that an appropriate shifting
recommendation is displayed to the user of the motor vehicle 1.
LIST OF REFERENCE NUMERALS
[0068] 1 motor vehicle [0069] 2 controller [0070] 2a engine
controller [0071] 2b transmission controller [0072] 3 internal
combustion engine [0073] 4 transmission [0074] 5 cooling device
[0075] 5a cooler [0076] 5b coolant [0077] 6 temperature sensor for
4 [0078] 7 temperature sensor for 5b [0079] 8 shifting
recommendation display [0080] 9 CAN bus [0081] 10 method for
controlling 1 [0082] 11 determining the target minimum rotational
speed [0083] 12 determining the target gear setting [0084] 13
controlling the transmission [0085] 14 issuing the shifting
recommendation
* * * * *